Time delay switch



p 1969 J, M. MASSANOVA ET AL 3,465,108

TIME DELAY SWITCH Filed Aug. 15, 1967 I. 2 Sheets-Sheet 1 IO INVENTORS.

JOSEPH M. MASSANOVA VINCENT R. MELSO ATTORNE p 2, 1969 J. M. MASSANOVA T AL 3,465,108

TIME DELAY SWITCH Filed Aug. 15, 1967 2 Sheets-Sheet z INVENTORS. JOSEPH M. MASSANOVA VINCENT R. MELSO ATTORNEY United States Patent 3,465,108 TIME DELAY SWITCH Joseph M. Massanova, Philadelphia, and Vincent R. Melso, Broomall, Pa., assignors to Joseph M.

Massanova, Philadelphia, Pa.

Filed Aug. 15, 1967, Ser. No. 660,753 Int. Cl. H01h 43/02 US. Cl. 200-33 3 Claims ABSTRACT OF THE DISCLOSURE A time delay switch of the mercury contact type incorporating an integral fixed baffle and a movable member cooperating therewith to form a mercury retaining valve operable upon rotation of the switch, the said valve being provided with a small aperture to allow continuous mercury leakage therethrough.

This invention relates in general to electrical switches of the mercury type, and more particularly is directed to a time delay switch arranged to slowly interrupt and quickly complete an electrical circuit.

The instant invention finds particularly utility in the field of small electrical heating appliances, such as irons and is designed as an additional safety factor in the circuit to permit the device to become automatically de-energized upon the expiration of a predetermined period of non-use. The incorporation of such a device in the heating appliance circuit will insure that the appliance automatically and positively disconnects from the source of electrical power and thus assures complete safety from fire in the event the appliance is inadvertently left energized after use.

Prior workers in the field have employed mercury cut out switches in connection with electrical tiatirons. These switches operated on the principle of heating the mercury until it vaporized and then condencing the vapors in a secondary chamber that was remote from the area of the electrical contacts. In such a manner, after an extended period of time, sufficient mercury would become vaporized and thus lower the mercury level below the contacts to interrupt the circuit. Such prior art devices were generally satisfactory in use but were sluggish in operation and required increased power consumption for vaporization purposes. Further the reliability of prior art devices could be adversely affected by tilting the iron to a plane other than horizontal.

It is therefore an object of the instant invention to provide an improved time delay switch of the type set forth.

It is another object of the instant invention to provide a time delay switch of the mercury type that incorporates an integral mercury retaining valve.

It is another object of the instant invention to provide a time delay switch of the mercury type that includes integral fixed an movable mercury flow controlling construction.

It is another object of the instant invention to provide a mercury time delay switch that is rotatable from a circuit open position to a circuit closed position.

It is another object of the instant invention to provide a time delay switch of the mercury type including an integrally arranged baffle designed to control the flow of mercury, said baflle permitting rapid flow of mercury when in its initial position and said bafile operating to retard the flow of mercury when rotated to its time delay position.

It is another object of the instant invention to provide a time delay switch of the mercury type that incorporates a mercury retaining enclosure and an integral valve that has been designed to retard the flow of mercury in one "ice direction and to permit rapid passage of the mercury in the other direction.

It is another object of the instant invention to provide a time delay switch of the mercury type that is simple in construction, inexpensive in manufacture and trouble-free when in use.

Other objects and a fuller understanding of the invention will be had by referring to the following description and claims of a preferred embodiment thereof, taken in conjunction with the accompanying drawing wherein like reference characters refer to similar parts throughout the several views and in which:

FIG. 1 is a front perspective view of an electrical iron incorporating the instant invention, a portion of which has been broken away to expose the novel time delay switch.

FIG. 2 is a reduced view of an iron in the horizontal or operating position.

FIG. 3 is a reduced view of an iron in the vertical or resting position.

FIG. 4 is a partial, enlarged, perspective view of the time delay switch of FIG. 1 when the iron is in its operating position.

FIG. 5 is a partial, enlarged, perspective view of the time delay switch of FIG. 1 when the iron has been rotated to its resting position.

FIG. 6' is an enlarged perspective view of the time delay switch in the position of FIG. 5, portions of which are broken away to expose the interior construction.

FIG. 7 is an enlarged perspective view of the time delay switch in the position of FIG. 4, portions of which are broken away to expose the interior construction.

FIG. 8 is an enlarged perspective view of a modified type of valve in the open position, portions of the mercury container being broken away to expose the internal construction.

FIG. 9 is a cross-section taken along line 99 of FIG. 8, the dotted lines representing the valve in closed position.

FIG. 10 is an elevational view of an iron, partly broken away to expose a modified time delay switch.

FIG. 11 is an enlarged view of the time delay switch of FIG. 10.

Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of our invention selected for illustration in the drawings and are not intended to define or limit the scope of the invention.

Referring now to the drawings, in FIG. 1 we show an electrically energized iron A which incorporates a tim delay switch 10 in accordance with the instant invention. The iron may be either of the steam or dry type empowered by electricity in the usual manner, as by an electrical cord 12. The switch 10 is integrally, operatively arranged within the iron construction, and if desired, a cover plate, provided with a level indication opening, may be afiixed to the body of the iron A to permit a visual observation of the position of the mercury 18.

The switch 10 connects in series with the heating element (not shown) of the iron and employs a pair of electrodes 20, 22 operating in conjunction with liquid mercury 18 for circuit controlling purposes in the conventional manner. Referring now to FIGS. 4 and 5, the time delay switch includes an arcuate, tubular mercury container 24 of uniform circular cross section that preferably turns through three-quarters of a circle to provide adequate mercury storage space. The remote end 26 of the container is integrally formed with the sidewalls thereof to provide a leakproof receptacle. The container connection end 28 constricts to a narrow open neck 30 and receives the electrodes 20, 22. The electrodes 20, 22

a are arcuately bent to conform to the general configuration of the container 24 and are cemented or otherwise fastened at the neck 30 to provide a leakproof end closure which also serves to space the electrodes within the container. A two conductor cord 32 carries current to and from the electrodes. The electrical connections between the cord and the electrodes may be made in any approved manner well known in the art.

A hinged check valve 34 is positioned within the container 24 intermediate its ends 26, 28 and controls the flow of mercury within the container. The valve comprises a circular mounting 36 which is pressed or otherwise arranged in a liquid tight circumferential engagement with the interior surface of the container 24. A horizontal hinge 38 medially divides the valve into a fixed, liquid retaining upper baffle 40 and a horizontal swinging lower gate 42. The fixed bafile 40 may be integrally formed with the circular mounting 36 if so desired to facilitate construction. An aperture 44 pierces the baffie 40 at the approximate center thereof and serves to permit mercury liquid to trickle through as will hereinafter he more fully explained.

Referring now to FIG. 7, it will be observed that the valve 34 is disposed substanitally vertically within the container 24 when the iron is placed in the operating position as illustrated in FIG. 2. In this position, both ends 26, 28 of the container face upwardly as shown in FIG. 4 and the mercury liquid 18 seeks to equalize its height in the upwardly arced portions of the container which are defined on either side of the valve 34, The hinged lower gate 42 swings with the flow of mercury and permits unrestricted flow through the passage 46 towards the electrodes 20, 22. Thus when the iron is moved to its operating position of FIG. 2, the mercury rushes towards the electrodes and the electrical circuit is almost instantaneously completed.

As can best be observed in FIG. 6, when the iron A is placed in its standby position by standing on the heel as shown in FIG. 3, the valve 34 is positioned substantially horizontally within the container 24. When the iron is rotated to the position of FIG. 3, the lower gate 42 swings against the mounting ring 36 and forms a substantially liquid tight seal therewith. It can be observed that all mercury resting in the container between the valve 34 and electrodes will be trapped above the valve and thus electrical contact between the elecrodes by means of the mercury will be continued. With the valve in its closed position, the aperture 44 permits the leakage of fluid and the mercury will fall by gravity into the adjoining section of the container 24. It can readily be appreciated that the length of elapsed time between rotating of the iron to its FIG. 3 position and the breaking of electrical contact is a function of two variables, namely the depth of emersion of the electrodes in the mercury and the size of the aperture 44. By increasing the aperture opening, the time delay period will be decreased. Also, by decreasing depth of electrode emersion in the fluid, the time delay period will also decrease. It is thus demonstrated that the elapsed time delay period necessary to interrupt the operating circuit can readily be regulated as desired.

Referring now to FIGS. 8 and 9, a modified type of mercury controlling valve is set forth. In this modification, a valve seat 48 transversely divides the container 24 intermediate its ends 26, 28. The valve seat may be ccmented or otherwise afiixed to the interior of the container to provide a fluid-tight peripheral junction '52. The valve seat is positioned with its inclined seating surface 50 looking in the direction of electrodes 20, 22 so as to permit maximum flow thereto. A movable valve 54 longitudinally travels within the container 24 and is fabricated with a frusto-conical nose 56 for sealing engagement upon the valve seat 48. A spring wire valve travel limiter 58 is pressed into the container 24 and is secured in position between the electrodes 20, 22 and the valve 54 by the spring action of the limiter legs 60, 62, 64 against the interior of the container 24. The legs 60, 62, 64 are axially aligned and are equally bent to form a transverse buffer section 66. The junction 68 of the legs is positioned off center to permit unrestricted flow through the aperture 70 as hereinafter more fully set forth. The limiter should be positioned within the container a sufiicient distance from the valve seat 48 to allow full flow about the valve 54 when the iron is in the operating position of FIG. 2. Also, the limiter 58 should be positioned close enough to the valve seat 48 so as to trap a sufiicient quantity of mercury for time delay purposes when the iron is moved to its FIG. 3 posit1on.

The valve 54 is cylindrical in shape, of diameter to readily fit Within the container. An integral frusto-conical nose 56 forwardly extends from the valve and seals against the valve seat 48 when the iron is rotated to its standby position. In operating position, the flow of mercury toward the electrodes due to the forces of gravity opens the valve and the subsequent equilibrium conditions function to keep the valve open. A plurality of at least eight front and rear valve positioning pins 72 extend radially from the surface of the valve 54 and serve to maintain the axial alignment of the valve within the container 24. The pins 72 are in sliding engagement with the interior of the container and serve to insure positive seating of the valve nose 56 upon the valve seat 48 at all times when the iron is rotated to the standby position. An axially aligned aperture 70 pierces the valve 54 to permit continuous mercury leakage when the iron is in standby position. When a suflicient quantity of mercury has trickled past the valve, the electrodes 20, 22 become expdsed and the cincuit is interrupted. 'The period of time delay between rotating the iron to the FIG. 3 position and the de-energizing of the operating circuit is variable depending upon the diameter of the aperture 70 and the distance between the limiter 58 and the valve seat 48. By regulating either or both of the variables, the time delay period may be conveniently modified.

In FIGS. 10, 11, we show a modified time delay switch wherein a hollow cylindrical container 76 rests in an inclined position when the iron is in the resting position of FIG. 3 as shown. A pair of electrodes 78, 80 insert through the bottom of the container 76 and the opening therein is sealed in any wellknown manner. A hinged check valve 74 transversely divides the container above the electrodes 78, 80 and comprises a circular mounting 84 afiixed to the interior of the cylinder in a leak-proof, peripheral junction. A gate 86 pivots about the hinge when the iron is in operating position and allows free flow of mercury 82 downwardly. When the iron is rotated to its FIG. 10 position, the gate 86 closes upon the mounting 84, thereby trapping a quantity of mercury and maintaining circuit continuity through the electrodes. In this rotated position, the mercury trickles through the aperture 88 for a predetermined period of time until the circuit is broken.

Although we have described our invention with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.

We claim:

1. In a time delay syitch, the combination of (A) a tubular container (1) said container having one closed end and (2) a scalable open end, said open end being adapted to receive electrodes therethrough;

(B) a pair of electrodes within the said container,

(1) said electrodes being inserted through the said open end,

(2) said electrodes being positioned closer to the said open end; (C) a quantity of liquid mercury Within the container,

( 1) said quantity being less in volume than the volumetric capacity of the said container; (D) valve means operably atfixed within the container intermediate its ends;

(1) said valve means having a first position and a second position,

(a) said valve means permitting rapid flow of mercury towards the said electrodes when in first position, and

(b) said valve means permitting a greatly restricted flow of mercury away from the said electrodes when in second position,

(2) said valve means including movable and stationary means,

(a) said movable means including a cylindrical valve having a diameter less than the interior diameter of the said container,

(b) a plurality of valve positioning pins radially extending above the surface of the said valve,

(.1) said pin axially aligning the valve within the container, and

(.2) the said pin having sliding contact with the interior surfaces of the said container.

2. The invention of claim 1 wherein the said cylindrical valve has recpirocal motion along the longitudinal axis of the said container, and wherein the said valve is axially drilled to provide a small, axially aligned opening.

3. The invention of claim 1 wherein the said cylindrical valve has reciprocal motion along the longitudinal axis of the said container, and wherein the said valve is axially drilled to provide a small, axially aligned opening and valve travel limiting means affixed within the container between the said electrodes and l the said stationary means, the said valve travel limiting means being adjustably secured within the container.

References Cited UNITED STATES PATENTS 1,797,974 3/1931 Brandall ZOO-33.1 1,974,411 9/1934 Cole 200--33.1 2,119,944 6/1938 Mattern ZOO-33.1 2,206,436 7/ 1940 Spencer 20033.l 2,295,054 9/ 1942 Rudd ZOO-33.1 2,800,537 7/1957 Hesh ZOO-33.1

H. O. JONES, Primary Examiner 

